In semiconductor modules for switching high currents or high power levels (power semiconductor modules below), one or more semiconductor components (also referred to as semiconductor chips below) are usually mounted on substrates which comprise ceramic, for example.
A power semiconductor module having a metallic base plate is evident from EP 0 584 668 A1. A plurality of substrates which are electrically insulated from the base plate by means of an interposed insulating layer are symmetrically applied to the base plate. A plurality of power semiconductors which are electrically connected in parallel are symmetrically arranged on the conductor tracks of said substrates. The base plate can be pressed onto a cooling area (not described in any more detail) for the purpose of dissipating heat.
EP 0 584 668 A1 attends to the problem of asymmetrical parasitic inductances in the case of current paths which are not the same. A construction of semiconductor arrangements on separate substrates, their mounting on a common base plate and their optimal cooling are not addressed.
It is increasingly customary to arrange power semiconductors on separate substrates, to mount the latter on a common base plate and to cool them using the base plate. In the case of the substrate arrangement which can be gathered from EP 0 584 668 A1, a very inhomogeneous distribution of the pressing-on pressure between the base plate and the corresponding cooling area would result. It is conceivable to even out a pressing-on pressure produced in the edge region of the substrates by pressing-on apparatuses by means of a convex shape of the underside of the base plate over the entire base plate. However, a convex configuration of the underside of the base plate is complicated, and thus expensive, in terms of production technology and results in mechanical stresses in the base plate when mounted.